Of course

Bellatrix and Snape PWN!

As much as I love Snape and Bella, I gotta say that Dumbledore and Grindelwald would win. Dumbledore is roughly the most powerful wizard ever, so yeah. :)

I love Severus Snape and really don't like Dumbledore, but as powerful a combination as Bella and Severus make, Dumbledore and Grindelwald would be simply more powerful. None of the other teams would beat this combination either.

^ I feel so disloyal...

As much as I love Bella and Sev I just feel that Dumbledore and Grindelwald would have beat them in a duel.

Deja vu... is it me, or I have already commented on this one? Or was it second round? I'm going mad... it's studying. But tomorrow it'll end. So... yeah. Snape and Bella doN't stand a chance...
And yes, I know now. I commented on Tonks and Moody vs Voldemort and someone.

I think Bella & Snape are a team that could have a chance to win against these two!!!They are both really powerful and great duelists!!!

I adore Snape and am quite a fan of Bella, but there's no way they could have beat Dumbledore and Grindelwald. According to Albus, he himself was only a little bit better at duelling than Gellert.